Briggs engine will not fire up on LA115

[JLOCKE]

Have a la115 with Briggs & Stratton 31P6770144B1 engine will not start does turn over but has a hard time turning over but when spark plug out it turns over good when plug is in not so good has brand new battery and has spark is there a internal combustion problem need help!

 

[Auto Doc's]

From your description, it needs the valves adjusted so the compression release will work. If it still fights the compression after adjustment, the engine will need the camshaft replaced.

 

[JLOCKE]

From your description, it needs the valves adjusted so the compression release will work. If it still fights the compression after adjustment, the engine will need the camshaft replaced.

Okay i will check the valves what is the gap for both

 

[slomo]

Couple things ALL mowers and other outdoor power equipment "require" yearly. If they have valves then they need adjusting yearly. At least checked for proper gap/clearance.

Clean the cooling fins. Most of these are air cooled. Do I need to elaborate here?

Every 5-8 years, engines need decarboned in the cylinders and valve areas. All this this is in your and every other engine manual out there.

 

[Tiger Small Engine]

Okay i will check the valves what is the gap for both

Are you able to correctly adjust valves? I ask because you asked what is spec on valves for this engine. It is simply a matter of looking it up. Intake: .004”
Exhaust: .006”
Good luck.

 

[JLOCKE]

Yes adjusted the valves and no different still locking up

 

[Auto Doc's]

Sounds like everything is indicating the camshaft compression release has failed. Worse case, one or the cam lobes are very worn down.

One quick test you can try is spin the motor backwards by hand from the point it stops at. Then remove the air cleaner and block the intake. Try to crank the motor and see if it fires right up while blocking the intake.

This reduces the intake air, and it will not fight the higher compression. When it fires off, remove the intake blockage.

There are examples of this on You Tube.

Let us know what you find.

 

[sgkent]

put a compression gauge on it. If it is 60 - 70 psi then the release is working. If it is well over 100 then the release is not working. That can be anything from a piece of swarf caught in the mechanism to a failed part.

 

[Freddie21]

i wish all people posting would use punctuation it makes it so hard to read run on sentences and try to figure out what is being said i know the young ones are lazy and maybe lack proper public education send all your replies to #learnenglish

 

[farmerdave1954]

AMEN! In another thread I was reading, the poster ran on without a single punctuation mark or capital letter for 14 lines, all one big sentence. Liked to never figured out what he was talking about because I couldn't tell where he left one subject and started another. Add to that a bunch of misspelled, truncated and abbreviated words and I almost gave up trying to decode it. Sometimes I just move on rather than try to figure it out. Did you know they don't teach spelling, grammar, punctuation, or cursive handwriting in many schools anymore?